Metal coordination study in Crown thioethers through DFT calculations and hyperfine parameters

R. NASCIMENTO; F. CAMARGO DALMATTI ALVES DE LIMA; M. BROWN GONÇALVES; L. A: ERRICO; H. M. PETRILLI

Campos de Jordao

Congreso; XIII Encontro da Sociedade Brasileira de Materiais (SBPMat XIII); 2013

Sociedade Brasileira de Materiais

The understanding of metal coordination of the chelates have high impact in many different areas, such as solubilization of inorganic compounds, separation of inorganic salts, liquid-membrane separation, liquid-liquid extraction, ion sensitive electrodes, and in organic synthesis as phase transfer reagents. Hyperfine techniques can be used to elucidate local environments of heterocyclic ligands as Crown thioether which its ion-ligand affinity can be correlated with the macrocycle hole size, shape and plasticity. In this work structural and electronic properties of [C12H24S6X], [C13H26S6OX] and [C14H28S6OX] (X: Ag+, Cd+/2+) Crown thioether complexes are investigated within the framework of the Density Functional Theory (DFT) using the Projector Augmented Wave (PAW) method. The theoretical results are then compared with Timedependent Perturbed Angular Correlations (TDPAC) experiments performed using the 111Ag→111Cd probe to understand the metal coordination. This comparison allows to state that the measured EFG at the Cd sites correspond to the case of +2 charge state in the Ag+ coordination sphere (i.e., before the structural relaxations are completed). These results are discussed in terms of the characteristics of the TDPAC 111Ag→111Cd probe and the time window of the measurement.